Zig-zag sewing machine



Aug. 22, 1950 J. GALKIN ZIG-ZAG SEWING MACHINE Filed March 22, 1949 :s Sheet-Sheet 1 JOSEPH GALKIN INVENTOR ATTORNEY Aug. 22, 1950 J. GALKIN 2,519,452

ZIG-ZAG SEWING MACHINE Filed March 22, 1949 5 Sheets-Sheet 2 Mi i I'Hmjl'i l i i Hip" 9 ll i i w JOSEPH -GALKIN JNVENTOR 5: BY M l// ATTORNEY Aug. 22, 1950 J. GALKIN ZIG-ZAG SEWING MACHINE Filed March 22, 1949 3 Sheets-Shed: 3

JOSEPH GALKIN BYW M ATTORNEY Patented Aug. 22, 1950 UNITED STATES PATENT OFFICE ZIG-ZAG SEWING MACHINE Joseph Galkin, New York, N. Y.

Application March 22, 1949, Serial No. 82,859

'Glaims.

This invention relates to an attachment for converting a looper type double lockstitch straight line stitching sewing machine into a zigzag stitching sewing machine.

An object of this invention is to provide a simplified vibrating mechanism whereby the needlebar is vibrated by a lever mounted on the presser-bar as an axis to produce zig-zag stitching.

Another object of this invention is to provide simplified mechanism for actuating the vibratory lever, comprising a main shaft which is partly housed in an enclosed and sealed oil chamber, and a bracket supported upright shaft passing into the oil chamber and being operatively connected at its lower end with the main shaft for rotation thereby, and a link connecting the lever with the upper end of the upright shaft.

Another object of this invention is to mount an adjustable eccentric on the upper end portion of the upright shaft and to secure the link to the adjustable eccentric, thereby providing variations in the amplitude of the vibrations of the needle.

Another object of this invention is to provide upright bearings in the lever for the needle bar, whereby parallel vertical reciprocations are imparted to the needle bar.

With the above and other objects in view, the invention will be hereinafter more particularly described, and the combination and arrangement of parts will be shown in the accompanying drawings and pointed out in the claims which form part of this specification.

Reference will now be had to the drawings, wherein like numerals of reference designate corresponding parts throughout the several views, in which:

Figure 1 is a front elevation of a looper type double lockstitch straight line stitching sewing machine having zig-zag stitching and differential feeding mechanism applied thereto.

Figure 2 is a fragmentary view, in elevation, taken as indicated by the arrows 22 in Figure l and drawn to a larger scale.

Figure 3 is a top plan view of the sewing machine shown in Figures 1 and 2.

In the illustrated embodiment of the invention, the numeral indicates the work-supporting base of a straight line stitching sewing machine modified to produce zig-zag stitching and which comprises the usual standard I I, having an overhanging hollow arm l2 with a head 13 at its free end.

In the head !3 is journaled a needle-bar l4 carrying a needle 15. The needle-bar I4 is reciprocated up and down by a needle lever [B mounted on a pivot shaft H. The needle lever 2 I6 is connected to the needle-bar l4 by a link l8. A looptaker I9 is oscillated and cooperates with the needle to form stitching as is well known in the art. The material worked upon is held down by a presser shoe 2!! carried by the presser-bar 2!. The presser-bar rests on a cloth plate 22 secured to and above the work supporting base I0.

A bell crank lever 25 has a two-part hub 26, 26', pivotally mounted on the presser-bar 2|. The upper face of the hub portion 26 rests against the lower face of a journal 21 fixed in the head l3. The lower face of the hub portion 26 rests against the upper face of a journal 28 fixed in the head l3. This arrangement prevents vertical movement of the lever 25.

One end of the lever 25 has an arm 29 having two upright bearings 30, 3| positioned in spacedapart relation. The bearings 30, 3| freely embrace the needle bar l4 and permit vertical reciprocations of the needle bar.

The other end of the lever 25 has a right-angular extension 32 which terminates in a rearwardly extending arm 33. The arm 33 has a downwardly directed ball-shaped extension 34 for a purpose to be described.

It is to be noted that parallel vertical reciprocations are imparted to the needle bar 14 when the lever 25 is vibrated. It is also to be noted that elongated openings 35, 36 are provided in the front portion of the head I3 to permit the bearings 30, 3| to freely vibrate in the head I3.

The driving means for vibrating the lever25 and the needle bar l4 comprises a bracket 48 having a boss 4! fixed to the work supporting base Ill and having an upright boss 42. Rotatably mounted in the boss 42 is a shaft 43. A carrier 44 is fixed to the shaft 43 by a, screw 45 and has a guideway 46 for a slide-block 41. A screw 48 threaded in the carrier 44 serves for adjusting the slide-block 41 in the guideway 46. 7

At the upper face of the slide-block 41 is a ball-shaped extension 50. A vibratory connection 5| is in operative engagement with the ballshaped extension 50 and with the ball-shaped extension 34 at the free end 53 of the lever 25. 7

Fixed to the main shaft 55 is a Worm 57 which is in meshed engagement with a worm gear 58 fixed to the lower end portion of the shaft 43. The gears 51 and 58 are designed to cause one revolution of the upright shaft 43 for two revolutions of the main shaft 55. Y i

It will thus be seen that when the main shaft is rotated, it will rotate the shaft 43. This will cause motion of the vibratory connection 5| which imparts vibratory motion to the lever"25 and the needle [5.

The needle bar l4 moves arcuately about the pivot on the presser bar 2| and the vertical reciprocatory motions of the needle bar l4 within the vertically aligned bearings are actuated by the needle lever I6 and the needle thus reciprocates solely in parallel vertical planes.

The gears 51 and 58 are enclosed in an oil box 69 which is secured to the work supporting base If] by screws 6|. As shown in Figure 1, it will be seen that the oil box is entirely clear of the standard l l.

The zig-zag mechanism is shown incorporated :in a sewing machine having positively driven feed-roller 6?. for differential feeding.

The feed-roller 62 is rotatably mounted on a horizontal stud 63 in a bracket or carrier 64 which is fixed to the lifter bar 2|. The feed-rolle 62 is mounted with its axis directly over a fourmotion feed-dog well known in the art.

The feed-roller 62 is rotated by a shaft 66. The carrier 64 is raised vertically by the presser-bar 2| which is slidably mounted in bearings in the head l3. The carrier 64 is also mounted for vertical sliding motion on a guide bar 68 secured in the head l3. The lifter-bar 2| may be raised by a horizontal lever 69 pivoted on a screw 61. When the presser-bar is raised, it raises the attached carrier 64 and the feed-roller 62. A leaf spring 10 bears at one end on a spring rest II and at the other end on the upper face of the lifter-bar 2| and this pressure is transmitted to the hub of the feed-roller 62.

The presser-shoe shank i2 is slidably mounted for vertical motion in a vertical guideway 13 in the carrier 6Q. Pressure is maintained upon the presser-shoe 26 by means of a spring 14 suitably fixed to the carrier 65 and pressing down at its free end on the shank 12.

Positive rotary step-by-step feeding movements is imparted to the shaft 66, to a universal joint '55, and to the feed-roller 62 by an oscillatable clutching detent carrier (not shown) mounted within a casing '16, fixed to the shaft66. A clutch arm T! is freely rotatable on the shaft 66 and is fastened to a clutching detent carrier in the casing 16. The arm 11 is pivotally connected to a link 78. lhe other end of the link 78 is pivotally connected at one end to a bell-crank lever 19. At the opposite end, the lever 19 is pivotally connected to a pitman 80 having as strap 8| in engagement with an eccentric 82 on the main shaft 55.

In order to prevent reverse movement of the shaft 66, and the feed-roller 62, I provide a braking detent carrier (not shown) mounted within the casing 76.

The clutch detent carrier and the braking detent carrier are mounted on the shaft 66 to work in opposite directions and may be in the form shown and described in Patent No. 1,985,406, issued to Nathan B. Galkin,'dated December 25, 1934.

In accordance with the patent statutes I have described and illustrated the preferred embodiment of my invention, but it will be understood that various changes and modifications can be made therein without departing from the spirit of the invention as defined by the appended claims.

I claim:

1. An attachment for converting a looper type double lockstitch straight line stitching sewing machine having a needle-bar, a presser-bar, a -work supporting base and a main shaft below said base into a zig-zag stitching sewing machine;

comprising a bracket secured to said work sup' porting base and having an upright shaft rotatably mounted therein, a worm on said main shaft in meshed engagement with a worm gear on the lower end portion of said upright shaft, said gearing being arranged to cause two revolutions of said main shaft for each revolution of said upright shaft, an adjustable eccentric mounted on the upper end portion of said upright shaft, a lever pivoted on said presser-bar and having one end freely embracing said needle-bar, thereby permitting vertical movements of said needle-bar, said lever having an upright extension mounted in said head to prevent vertical movement thereof, and a link connecting the other end of said lever with said eccentric to impart vibratory motion to said lever and to said needle-bar to cause zig-zag stitching.

2. An attachment for converting a looper type double lockstitch straight line stitching sewing machine having a needle-bar, a presserbar, a work supporting base and a main shaft below said base into a zig-zag stitching sewing machine; comprising a bracket secured to said work supporting base and having an upright shaft rotatably mounted therein, said shaft being operatively connected at its lower end with said main shaft for rotation thereby, an adjustable eccentric mounted on the upper end portion of said upright shaft, a lever pivoted on said presserbar and having one end freely embracing said needle-bar, thereby permitting vertical movements of said needle-bar, said lever having an upright extension and being thereby mounted in said head against vertical movement, and a link connecting the other end of said lever with said eccentric to impart vibratory motion to said needle-bar to cause zig-zag stitching.

3. An attachment for converting a looper type double lockstitch straight line stitching sewing machine having a needle-bar, a presser-bar, a work supporting base and a main shaft below said base into a zig-zag stitching sewing machine; comprising a bracket secured to said Work supporting base and having an upright shaft rotatably mounted therein, a worm on said main shaft in meshed engagement with a worm gear on the lower end portion of said upright shaft, said gearing being arranged to cause two revolutions of said main shaft for each revolution of said upright shaft, an adjustable eccentric mounted on the upper end portion of said upright shaft, a lever pivoted on said presser-bar and having upright bearings embracing said needlebar, thereby causing movements of said needlebar in parallel vertical planes, said lever having hubs mounted in said head to prevent vertical movement of said lever, and a link connecting the other end of said lever with said eccentric to impart vibratory motion to said lever and parallel reciprocations to said needle-bar to cause zig-zag stitching.

4. An attachment for converting a looper type double lockstitch straight line stitching sewing machine having a needle-bar, a presser-bar, a Work supporting base and a main shaft below said base into a zig-zag stitching sewing machine; comprising a bracket secured to said work supporting base and having an upright shaft rotatably mounted therein and extending below said work supporting base, a worm on said main shaft in meshed engagement with a worm gear on the lower end portion of said upright shaft, said gearing being arranged to cause one revolution of said upright shaft for two revolutions of said main shaft, an adjustable eccentric mounted on the upper end portion of said upright shaft, a lever pivotally mounted on said presser-bar and having upright bearings embracing said needle-bar, means for preventing vertical movement of said lever, and a link connecting the other end of said lever with said eccentric to impart vibratory motion to said lever to cause zig-zag stitching with said needle reciprocating solely in parallel vertical planes.

5 An attachment for converting a looper-type double lockstitch straight line stitching sewing machine having a needle-bar, a presser-bar, a work supporting base and a main shaft below said base into a zig-zag stitching sewing machine; comprising a bracket secured to said work supporting base and having an upright shaft rotatably mounted therein, said shaft extending below said work supporting base, a Worm on said main shaft in meshed engagement with a worm gear on the lower end portion of said upright shaft, said gearing being arranged to cause one REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Onerdonk Dec. 3, 1907 Number 

